The present invention generally relates to a dielectric resonator device and more particularly, to a dielectric resonator device which utilizes resonance of TM.sub.110 mode in a rectangular cavity (referred to merely as TM.sub.110 mode hereinafter) or modified modes thereof.
With respect to a filter employing TM.sub.110 mode, there has conventionally been disclosed, for example, in Japanese Patent Laid-Open Publication (Tokkaisho) No. 53-119650, a filter in which resonators, each including a linear and single cylindrical or rectangular dielectric member as one stage resonator, are combined by the required number of stages in a casing functioning as a shield casing.
By the known arrangement as referred to above, however, there has been a limitation in responding to the demands for compact size and low cost which are the everlasting requests in the field of electrical communication equipment.
Meanwhile, for example, in a transmitting and receiving equipment for a base station of a mobile communication system, there is employed a channel filter which includes, as shown in FIG. 21, filters F1, F2, . . . and Fn in plurality which allow signals only of corresponding channels CH1, CH2, . . . and CHn to pass therethrough, and cables and the like for connecting output sides of said filters F1 to Fn. For the respective filters, cavity resonators, TE.sub.01.delta. dielectric resonator, TM.sub.010 dielectric resonator or the like are employed. In any case, since it is so arranged that the filters in plurality in the form of one unit for each channel are further combined to constitute the channel filter, there has been a strong request for reduction in size.